Diagnosis of attention-deficit and disruptive behavior disorders defines a group of disorders which have common properties. This group consists of attention-deficit hyperactivity disorder, conduct disorder and oppositional defiant disorder. in order to differentiate these disorders, which share similar properties, it is important to verify the existing differences. In this respect, differences between and distribution of perinatal factors in these three disorders were investigated. The study was conducted in the Child Psychiatry and Pediatric Neurology Departments over a 20-month period. Two hundred and seventy children out of 1,556 attendant with various complaints were diagnosed to have one of the following disorders: 121 had attention-deficit hyperactivity disorder, 50 had oppositional defiant disorder and 99 had conduct disorder. The prenatal and perinatal data of the patients were evaluated retrospectively by a neonatologist. With regard to the investigated parameters, none showed any significant difference between the three groups when compared. The three disorders, which share many similarities in terms of the symptoms, also show similarities in terms of perinatal factors. Since we did not find any study similar in design, our results, although statistically not significant, are discussed in light of the little data available.